Download Parts of a plant

Parts of the
plant and their
functions
Importance of
plants
 Without plants life on earth
would not exist
Plants:
 Primary source of food for
people and animals
 Produce oxygen
 help to keep us cool
 renew the air
Plants:
 slow wind speed
 provide a home for wildlife
 beautify surroundings
 perfume the air
 furnish building materials and
fuel
Parts of a plant
 *Four basic parts
 *leaves
 *stems
 *roots
 *flowers
Leaves
 the food factory of the plant
 *produce the food used by the
plant or stored for later use
Shape and size of
leaves
 vary among plants
 used for identification of
plants
Leaf arrangement
 *alternate
 *opposite
 *whorled
 arranged in a circle around the
stem
External leaf
structure
 *petiole - leaf stalk
 *leaf blade (leaf)
 has veins
 forms structural framework of
the leaf
Midrib
 *large center vein from which
all other leaf veins extend
Margins
 *edges of leaves
 assists in plant identification
Internal leaf
structure
 *epidermis
 skin of the leaf
 single layer of cells
 protects leaf from loss of too
much moisture
Guard Cells
 open and close the small pore
on the underside of the leaf
Stomates
 *allow the plant to breathe
and transpire
 *give off moisture
Chloroplasts
 *contain chlorophyll
 *located inside the cells
Photosynthesis
 process by which CO2 and
H2O in the presence of light
are converted to sugar and
oxygen
Chemical formula
 6CO2 + 6H2O
 -----> in reaction with sunlight
and chlorophyll ------>
 C6H12O6 (glucose) + 6O2
food
 *manufactured in the leaves
moves downward through the
stem to the roots
 used by the plant
 stored in stem or root and leaf
in the form of sugar, starch or
protein.
Respiration
 *plants respire 24 hours a day
 consume O2 and give off
CO2
 plants produce more O2
through ps. Than they
consume during respiration
and growth.
Stems
 *have two main functions
 *movement of water and
minerals from the roots upward
and movement of
manufactured food down
Stem functions
 *support of leaves and
reproductive structures
Stems also
 *used for food storage and
reproduction of plants
involving cuttings
 *Green stems manufacture
food just as leaves do
Internal Stem
Structure
 *phloem- bark, carries
manufactured foods down.
 *Xylem- wood, carries water and
minerals up.
 *Cambium- separates the 2 and
produces all new cells.
 *Characteristic of dicots
Internal Stem
Structure
 *dicot- dicotyledon, a plant
with 2 seed leaves
Monocot
 *Monocotyledon - a plant with
one seed leaf.
 *Have vascular bundles,
contain both xylem and
phloem in each small bundle
Monocot
 stems have no cambium
 cells enlarge to create size of
mature stem
Economic
Importance
 food
 building materials
Roots
 *Usually underground
 *functions:
 *anchor plant and hold upright
 *absorb water and minerals form
soil and conduct to stem
 *store food, & propagation
Root Structure
 internal
similar to stems
older roots have xylem,
phloem and cambian
external
root cap
produces continuous
supply of new cells
protects roots as they
push through soil
Structure
 *root hairs
*absorb moisture and
minerals
 *small roots
Functions other than
water and mineral
absorption
 *cash crops for food
carrots
beets
radishes
sweet potatoes
 propagation
Type of root
systems
 *fibrous- grasses
*easier transplanting
*shorter, smaller, more
compact
 tap root- carrot
*longer and fewer roots
REVIEW
Flowers, Fruits, and
Seeds
 pollination- color of flower attracts
insects to fertilize flower
 beginning of fruit and seed formation
 fruits and seed are attractive to
birds who eat and spread seeds.
 Reproduces plant
 some seeds carried on animals
coats
Parts of the Flower
 differ in size, shape, and
color, some basic parts
 sepal
green leaf-like part, covers
and protects bud before
opening
Petals
 are actually leaves
 usually bright colors to attract
pollinating insects.
Parts of the Flower
 stamens
male part of flower
has two parts
filament-stalk
Anther
anther- sac-like
structure on top of
filament, contains pollen
Parts of the Flower
 Pistil - female part
 in the center of flower
 has three parts
Pistil
 three parts
 stigma - top - sticky
 style - tube leading from
stigma to ovary
Ovary
 egg cells develop here
 grows to become fruit or
seedcoat
Types of Flowers
 complete
contains 4 main parts
Incomplete
 does not have all 4 main parts
Perfect
 has stamens and pistils
Imperfect
 lacks stamens or pistils
Types of Flowers
 monoecious
stamens and pistils are
found in separate flowers on
the same plant
ex: Corn
dioecious
 male or staminate flowers
found on one plant, female or
pistilate flowers on another
plant
 ex: holly